Scaffold



April 1968 F. D. ZEITLER 3,378,101

SCAFFOLD Filed Aug. 12, 1966 3 Sheets-Sheet 1 Fig.

I Frank/m 0. Ze/fler INVENTOR. 34 70 50 April 16, 1968 F. D. ZEITLER3,378,101

SCAFFOLD Filed Aug. 12, 1966 3 Sheets-Sheet 2 q; & Frank/m D; Ze/f/erINVENTOR.

E Q w k N BY M406 N Q Attorneys & Q

United States Patent 3,378,101 SCAFFOLD Franklin D. Zeitier, 208 W.Liberty St, Punxsntawney, Pa. 15767 Filed Aug. 12, 1966, Ser. No.572,625 15 Claims. (6!. 18216) The present invention generallyappertains to scaffolds and similar lifting devices, which are adaptedto support workmen at various working heights in relationship to avertical structure, and more particularly relates to novel improvementsin a mobile, vertically adjustable scaffold construction.

The provision of mobile scaffolds which are wheel mounted fortransportation from place to place and which have upright supportingmeans on a wheel carrying base, with platform supporting means mountedon the vertical supporting means for positioning thereby at variousheights are known. Such known constructions employ hoisting means forthe platform supporting means, so as to raise and lower the platform,the hoisting means generally being composed of a rotatable drumjournaled on the base and having cables which are extended over theupper ends of the vertical supporting means and attached to the platformsupporting means on the vertical supporting means.

The principal drawbacks, with such known constructions, are that theyare extremely expensive to manufacture and, therefore, very expensive topurchase and that the mobile base is not maneuverable enough for easyplacement in relation to the work, such as a vertical wall structure,and that the hoisting means is extremely complicated, cumbersome andalso disposed so that it can be subject to accidental breakage ormalfunctioning and can interfere with the movements of the workmen onthe platform and interfere with the hoisting of working materials to theworkmen, when they are on the platform, and the platform is raised abovethe vertical supporting means. In addition, the hoisting means is sostructurally related between the base mounted drum or winch operatingmeans therefor and the platform supporting means on the verticalsupports that the upward, maximum height of the supporting means isunnecessari- 1y limited and restricted.

Accordingly, an important object of the present invention is to providea scaffold which overcomes the foregoing drawbacks, attendant withknown, similar types of scaffolds or lifting devices and to provide aninexpensive, extremely compact and maneuverable scaffold.

Another important object of the present invention is to provide ascaffold which is movable in an erected condition or state in anextremely simple and most efficient manner for maximum maneuverability,and which is of a collapsible nature, whereby it may be easilytransported, in a collapsed and compact arrangement, from one work siteto another.

Another important object of the present invention is to provide ascaffold which includes a very simple, effective and easily and safelyactuated and controlled hoisting arrangement for raising and lowering aplatform to selected heights, .the hoisting arrangement being formed anddisposed so that it is protected from damage and so that the workmen areprotected and so that it does not present any structural interferencewith the movements of the workmen on the platform or with the handing ofmaterials to the workmen on the platform.

These together with other objects and advantages which will becomesubsequently apparent reside in the 3,378,191 Patented Apr. 16, 1968details of construction and operation as more fully hereinafterdescribed and claimed, reference being had to the accompanying drawingsforming a part hereof, wherein like numerals refer to like partsthroughout, and in which:

FIGURE 1 is an end eleva-tional view of a scaffold, constructed inaccordance with the present invention, and showing the platform in alowermost position;

FIGURE 2 is a side elevational View of the scaffold, showing theplatform in a raised position;

FIGURE 3 is a fragmentary end elevational view showing the platformdisposed above the upper end of the vertical supports therefor;

FIGURE 4 is a detailed, fragmentary perspective view, showing thestructural details of the hoisting arrangement in relation to thevertical supports and platform supporting means and showing thestructural details of the platform assembly;

FIGURE 5 is a fragmentary, longitudinal horiozntal sectional view, takensubstantially on line 55 of FIG- UKE 2;

FIGURE 6 is a transverse, vertical cross-sectional view, takensubstantially on line 6-6 of FIGURE 5;

FIGURE 7 is a transverse sectional view, taken on line 77 of FIGURE 2and illustrating a safety lock arrangement, and,

FIGURE 8 is a top plan view showing the scaffold in a collapsed orfolded condition resting on the mobile base frame for transportationfrom one working site to another working site.

Referring now more particularly to the accompanying drawings, thescaffold, generally designated by the reference numeral fl), comprisesan elongated base frame 12, which is of open rectangular form. The baseframe 12 includes opposing side frame bars 14 and 16, which are joinedat their opposing ends by transversely disposed end bars 18 and 28. Theframe bars are of noncircular cross-sectional shape for rigidificationpurposes.

The base frame 12 is further com-posed of transverse brace bars 22 and24, which extend between and are suitably secured, as by welding or thelike, to the side frame bars 1'4 and 15. The brace bar 22 is disposedparallel with and spaced inwardly from the end frame bar 2% and definestherewith one end section of the base frame, while the brace bar 24 isdisposed parallel with and spaced inwardly from the end bar 1e anddefines therewith an opposing end section of the base frame. The bracebars 22 and 24 support diagonally disposed, upwardly and longitudinallyextending brace rods 26 and 28 which are attached at their innerconverging ends to a longitudinally extending brace rod 39, which issuitably secured at its ends to the crossbars 22 and 24 and is disposedcentrally of the base frame.

Each of the end sections is provided with steerable, ground engagingwheel assemblies 32 and 34, which movably support the base frame 12.Each of the wheel assemblies has a draft connection means 36, so thatthe frame can be drafted or towed by a draft vehicle from either end,thereby rendering it more maneuverable for placing the frame easily andquickly in position relative to a vertical work structure, and making itmore mobile for drafting purposes when the frame is being transported bythe draft vehicle from one work site to another work site.

Each of the wheel assemblies and its associated draft or towingconnection 36 are identically constructed and, therefore, a detaileddescription of the steerable wheel assembly 3 2-, as shown moreparticularly in FIGURES 3 l, 5 and 6, will suffice for an understandingof the wheel assemblies and the associated draft connection 36.

The wheel assembly 34 comprises ground engaging wheels 38 and 4%, whichare rotatably mounted on stub axles 42 carried by the outer ends of anaxle 44. The axle 44 is supported by depending standards 46 and 48,which are welded to the outer ends thereof and secured, as by welding,to the underside of the crossbar 24, adjacent its ends. The diagonalbrace rods 26 and 28 extend upwardly from the standards 46 and 4% andare attached to the longitudinal brace rod 39, between the cross braces22 and 24. The stub axles 42 are mounted by conventional kingpinassemblies 55 to the outer ends 44 of the axle which is fixed at itsraised center portion 52. to a crossbar 54, which extends between thestandards 46 and 48, as shown in FIGURES 1 and 6.

A tie rod 56 is pivotally attached at its opposing clevis ends 58 toprojecting tongues or arms as on the stub axles 4'2. and the centralportion of the tie rod 56 is pivotally attached, as at at, to an arm 64,which projects rearwardly from a vertical collar 65. The collar 56 isrotatably mounted by a bracket means d8 on the underside of the centerportion 56 of the axle and is provided with a forwardly projectingtongue arrangement 69. A tow bar 70 is pivotally secured by a pivotassembly 72 at its rearward end to the tongue 69 for movement about ahorizontal axis. The tow bar 74) is provided on its outer end withconventional hitch means 74, whereby it can be readily and easilyattached to the hitch on a draft vehicle. Thus, by virtue of the tow ordraft bar 79, the base frame is drafted in a steerable manner.

As afore-stated, the wheel assemblies 32 and 34 are of identicalconstruction and operation, so that the base frame 12 can be draftedfrom either end and, when it is drafted from one end, then means isprovided for disposing the non-used tow bar in an inoperative positionand for rendering the associated ground-engaging wheels non-steerable,so that such wheels merely constitute tracking rear wheels.

iAs shown in FIGURE 2, such means comprises a pair of cars 76, whichextend downwardly and outwardly from each of the end bars 18 and 2t andbetween which the associated draft bar 70 is adapted to be disposed inthe raised position, as shown in dotted lines in FIGURE 2. The draft baris held captive between the cars by a retaining pin 78. Thus, thecaptive draft bar 70 is not only held in an inoperative position and isheld out of ground-engagement but also serves to lock the wheels of theassociated wheel assembly against steering movements.

'A scaffold construction 8% is carried by the base frame 12 andcomprises a pair of elongated tubular supports 82 and 84. Each of thesupports is of circular cross-section and is hollow and has open lowerand upper ends 86 and 88, respectively.

Each of the crossbars 22 and 24 is provided with a pair of upstandingapertured ears 9'0 and $2, the ears being slightly offset, lengthwise ofthe base frame, as can be appreciated from a consideration of FIGURE 8.The lower end portions 86a of each of the supports 82 and 84 areprovided with radial apertures, alignable with the apertures in the earsto receive pivot pins 94, whereby the supports 82 and 84 are pivoted tothe brace bars 22 and 24 for vertical swinging movement about axes,transverse of the longitudinal axis of the base frame. The supports 82and 84 are adapted to be disposed in rigid upright positions andpositioned substantially in alignment longitudinally of the base frame,as shown in FIG- URES 1 and 2. The supports are held in such upstanding,rigid and related vertical positions by brace rods. Thus, innermostbrace rods 95 and 93 have their lower ends secured by pins 100 toupstanding ears 182 and 104 on the side frame bar 14-, the ears beingdisposed substantially centrally of the frame bar. The brace rods 96 and93 are in crossed relationship and have their upper ends secured by pins106 to the supports 812 and 8d. Complemental brace rods 168 and 1-10have their lower apertured ends secured by pins 112 to upstandingapertured ears 114 provided on the upper face of the side frame bar 14,adjacent the crossbars 22 and 24. The upper apertured ends of the endbrace rods 168 and 116 are fixed by the pins 1% to the supports.

As can be appreciated from a consideration of FIG- URE 2, the innerbrace rods 96 and 98 and the outer brace rods 16% and 110 serve toretain the supports in secure and rigid upright positions. The pins 100,166 and 112 are removable, so that the supports can be disposed ingenerally horizontally collapsed positions res ing on the end sectionsof the base frame, as shown in FIGURE 8.

When the supports are erected, they are held in their secure, uprightpositions by the brace rods, which are attached to the ears on the sideframe bar 14 and to the supports by the removable pins.

Supportin members 116 and 118 constitute part of the scaffoldconstruction and are slidably sleeved on the supports and constitute themeans for supporting the platform assembly 121 and for raising andlowering the same through a hoisting means, as will be described. Thesupport members 116 and 113 are in the nature of sleeves, which areslidably disposed on the tubular supports 82 and 8 Means is provided forpreventing rotation of the supporting members 116 and 118 relative totheir associated supports and for guiding the supporting members insmooth sliding manner along the axial extent of the supports. Such meansincludes the provision of a radially outstanding rib or rail 122 on eachof the supports, the ribs extending substantially the full length of thesupports and being formed on the face of the supports that faces theside frame bar 14. The supporting members 116 are axially split from oneend to the other, so as to provide axial grooves or slideways 124, whichslidably engage the sides of the rib or rail 122, thereby preventingrelative rotation between the supporting members and the supports andinsuring a free, sliding movement of the supporting members.

Means is provided for raising and lowering the supporting members inconsort on their associated, upstanding and rigidified supports 82 and84 and such means essentially comprises a hoisting arrangement. Thehoisting arrangement, generally designated by the reference numeral 126,comprises an elongated rotatable shaft 128, which extends lengthwise ofthe base frame and is disposed parallel with and in adjacency with andinwardly of the side frame bar 14. The opposing ends of the shaft 128are rotatably journaled in journaling means 130, which is supported bysupport brackets 132 that are attached to the adjacent standards 48, asshown in FIGURE 5. The shaft 128 lies below the side frame bar 14, asshown in FIGURE 2, and is provided on its end portions, adjacent thejournaled ends, with drum means 134 and 136. The drum means are actuallycomposed of annular plates 138 and 140, which are suitably fixedlycircumposed on the end portions of the shaft and which are spaced apartand define with the circumferences of the end portions of the shaft thewinding drums 134 and 136, on which elongated flexible elements, such ascables 142 and 144 are wound.

The cables 142 and 144 are controlled by the rotation of the actuatingdrum shaft 128 and the cables operate in consort to raise and lower theassociated supporting members in an even, commonly moving manner, thus,the cable 142 is structurally related with the supporting memher 116while the cable 144 is structurally connected to the supporting member113. Since such structural arrangement of the cables with theirassociated supporting mem- 3 hers is the same, in each instance, adetailed explanation of the structural arrangement of the cable 142 withthe support 82 and associated supporting member 116 will sufiice.

In this respect, as shown in FEGURES 4-6, the crossbar 24 is provided onits underside with a depending pair of cars 146, which carry a pin oraxle 148, on which a pulley or sheave 150 is rotatably disposed forrotation about an axis, parallel to the longitudinal axis of theelongated mobile base frame 12. The flexible element 142 leaves off fromthe immediately adjacent drum or winch means 135 and passes under thepulley 150, which is disposed below the lower open end 86 of the support82, so that the elongated element is almost completely enclosed and iscompletely and conveniently guided from the drum means 13% into thetubular support 82.

The flexible element 142 extends movably upwardly in the support 82,which is provided at its upper end portion 152, as shown in FIGURE 4,with an upper guide means 154, which is constituted by a rotatablepulley 156. The upper end portion 152 of the support 82 is formed withan axial end notch or cutout portion 15 8 on the face which carries theguide rib or rai 122. The pulley 154 is rotatably mounted on a pin orale 159, fixed internally of the upper end portion and disposeddiametrically thereof,

:ith the axis of the pulley 154 paralleling the axis of the pulley 150and the axes being in substantially vertical alignment and beingdisposed parallel with the longitudinal axis of the base frame 12. Theprojecting portion of the pulley 154 which extends slightly beyond theinternal diameter of the tubular support 32, does not extend beyond theradially projecting extent of the rib or rail 122, as can be appreciatedfrom a consideration of FIGURES 1 and 3, so that the supporting memberscan move upwardly past and above the upper ends of the supports 82 and34. Thus, the upper guide element or pulley 154, by virtue of the rib orrail 3.22 in the given, specific instance, is disposed entirely withinthe supporting or working area of the support 82, whereby it is possiblefor the sleeve-like supporting members 116 and 113 to ride over andabove the pulleys and the upper ends of their associated supports 82 and84.

The flexible element 142 passes over the pulley 154 and extendsexternally of the support and is attached at its outer end 162 to a hookmeans H4, which is in the form of a closed loop or eyelet, that issecured to a lateral projection 166 on the face 168 of the supportingmember 116, adjacent its lower end. The book means 164 is provided onthe face 168, which faces toward the end 18, so that the flexibleelements or cables 142 and 1 4 are fixed to their associated supportingmembers 116'and 118 by anchoring hook-like means 164 that is provided onthe faces of the supporting members that are directed toward the ends ofthe base frame 12 and are disposed in oppositely facing directions.Also, it is to be noted that the face 168 or, otherwise stated, thehoololike anchoring elements or means 164 are disposed substantiallynormal to the slotted faces of the associated supporting members, whichface the side frame bar member 14. This permits the flexible elements toextend externally and be anchored to the supporting members in a mannerso as to not interfere with the sliding movements of the supportingmembers on their associated supports and in a manner so that theflexible elements are not in any way impeded or interfered with by theplatform assembly 120 nor do they olfer any obstruction to workmen onthe platform assembly or to the handing of materials to workmen on theplatform assembly 12!).

Means is provided for rotating the shaft 128, so as to control inconsort the raising and lowering movements of the supporting members 116and 118 for the platform assembly 120, such movements being controlledby the unison operation of the flexible elements 142 and 144. Theactuating means for the shaft 128 comprises a pinion 1719, which isfixed on the shaft 128 and enclosed in a housing 172, that is supportedby a bracket means which extends laterally inwardly from and is anchoredto the side frame bar 14, as shown in FIGURES 5 and 6. An actuatingshaft 174 is rotatably journaled in a bearing sleeve 176, which formspart of the housing and is provided with a worm gear 17 S enmeshed withthe pinion 179 so as to rotate the shaft 128. The actuating shaft 174terminates in an outer end 180, which is noncircul r, and which isadapted to receive a coupling socket 182 for a handwheel 184.

The handw-heel 184 is adapted to be manually rotated, so as to rotatethe shaft 128, and through the enmeshed worm gear and pinions 17S and17C} for thereby operating the drums 134 and 135, so as to control thehoisting or lowerin actions of the flexible elements or cables 142 and144.

.V-hile the manually operated handwheel will work most efiiciently andwill enable the scaffold to be produced and sold at a lower cost, it isto be understood that an electric motor can be substituted for thehandwheel and can be mounted on the side frame bar 14 and have itsarmature shaft drivingly associated or connected with the actuatingshaft 17 i or directly with the shaft 128, the motor being of anyelectrical type and being operated by storage batteries and theenergization thereof being controlled by switch means positioned on theplatform assembly 120 in an accessible manner so that workmen on theplatform 8.356211 ly 128 can control, in a remote manner, the rotativemovements of the shaft 128.

The platform assembly 126 comprises arms 186 and 188. The arms are inthe form of angle irons, as shown in FIGURE 4, and project laterallyfrom their associated supporting members. As shown in FIGURE 4, the arm186, when the support 32 is in an upright vertical position and thesupporting member 116 is operatively mounted thereon, under the controlof the elongated flexible element 142, projects laterally from thesupporting member and faces toward the side frame bar 16 or in theopposite direction from the rail and slide arangement. The arm 1% is ofright angular, cross-sectional configuration, preferably being made froman angle iron, and, therefore, has a flat, substan 'ally horizontallydisposed upper face 188 and a vertical face or flange 1%. An attachingplate 192 is formed on the inner end of the vertical face 195 and issecured, as by welding 194, to the associated supporting member 116.Thus, the arms are rigid with their associated supporting members.

An achoring or attaching angle iron 1% overlies the arm and has an upperface or side 198, which overlies the upper surface of the upper face 188of the arm and a vertical flange 2%, which is formed with apertures 2&2that are adjustably registrable with apertures 2% formed in the verticalside or flange of the arm and adapted to receive bolt or similarfastener assemblies 2116. The anchoring or attaching angle irons 196,which are bolted by the bolt assemblies 2% to the arms, support ahorizontal platform 2%, which is made up of side by side, parallelplanks 21H) that are held together by a frame assembly 212 which isfastened, as by welding 214, to the faces 198 of the anchoring angleirons.

A guard rail structure 216 is provided on the inner, longitudinallyextending side of the platform, since the outer lon'ritudinal side edgeportion of the platform will be in adjacency to a vertical structure,such as the well of a building and will not require any guard railstructure. The guard rail assembly 216 comprises an elongated,longitudinally extending handrail 218, which is attached by supportingarms 226 to the platform support 212, the lower ends of the arms 22%being pivoted by pivot pins 222 to upstanding ears 224-, as shown inFIG- URE 4. A locking, hinge-type brace 225 is pivotally interconnectedbetween one of the planks and each of the supporting arms 22% for thehandrail, as shown in FIG- URE 4.

As shown in FIGURE 7, spring-urged locking or hitching detents 228 arecarried by the supporting members for automatic safety latchingengagement with a series of vertically arranged springs 239 in thesupports. The detents are manually releasable and constitute a safetyfactor in the event of malfunction of the hoisting means, such asbreakage of one of the hoisting cables.

it can be appreciated, from a consideration of FIG- URE 8, that when thescaffold is not in use, the vertical brace rods 96, as, 168 and 11s areremoved by simply removing the attaching pins therefor and the supports82 and 34 are lowered into substantially or generally horizontalpositions resting on the base frame and disposed in side-by-siderelationship. The supporting members and arms are still carried by thesupports and the detached brace rods can be placed on the base frame 12so that the entire scaffold, in its knocked down or collapsedrelationship, can be transported to another working site by a draftvehicle attached to either end of the mobile frame, as afore described.

When the supports are in upright positions, they are held in suchpositions by the brace rods and the flexible elements 142 and 144 areattached to the supporting members 116 and 118 so as to control thevertical movement thereof, with the platform assembly 120 attached tothe arms. The foregoing is considered as illustrative only of theprinciples of the invention. Further, since numerous modifications andchanges will readily occur to those skilled in the art, it is notdesired to limit the invention to the exact construction and operationshown and described, and accordingly all suitable modifications andequivalents may be resorted to, falling within the scope of theinvention as claimed.

What is claimed as new is as follows:

1. A scaffold comprising an elongated base frame having opposing endsections, an elongated tubular support carried by the base frameadjacent each end section, means mounting the supports on the base framefor positioning of the supports in rigid upright positions and disposedsubstantially in alignment longitudinally of the base frame, eachsupport having an upper and a lower end, a supporting member slidablysleeved on each support, a platform assembly carried by the supportingmembers and including a substantially horizontally disposed platformoverlying the base frame and extending between the supports, rotatablewinding means carried by the base frame, a pair of elongated flexibleelements wound on and actuated by the winding means in synchronizedfashion, a lower guide means disposed below the lower end of eachsupport, an upper guide means carried by the upper end of each support,one of said flexible elements being passed under the lower guide meansfor one support and extending movably upwardly in the one support andbeing passed downwardly over the upper guide means on the one supportexternally of the support, the other of said flexible elements beingpassed under the lower guide means for the other support and extendingmovably upwardly in the other support and being passed downwardly overthe upper guide means on the other support externally of the support,and means attaching the flexible elements to the supporting members formoving the supporting members in consort on their associated supports.

2. The invention of claim 1, wherein said upper guide means for eachsupport is disposed entirely within the working cross-sectional area ofthe support so that the supporting members can extend above the upperends of the supports.

3. The invention of claim 1, wherein said upper guide means for eachsupport includes a rotatable pulley, means mounting the pulley in avertical position at the upper end of the support so that the supportingmembers can be raised into uppermost positions extending upwardly abovethe upper ends of the supports.

4. The invention of claim 1, wherein said lower guide means for eachsupport includes a pulley, means carried by the base frame for rotatablymounting the pulley in a vertical position below the lower end of thesupport.

5. The invention of claim 1, wherein said upper guide means for eachsupport includes a rotatable pulley, means mounting the pulley in avertical position entirely within the supporting area of the support,said lower guide means for each support including a rotatable pulley,means carried by the base frame for mounting said last pulley in avertical position below the lower end of the support, said pulleys beingrotatable about axes parallel to the longitudinal axis of the baseframe.

6. The invention of claim 5, wherein said winding means includes anelongated shaft disposed parallel with the longitudinal axis of the baseframe and extending substantially the length of the base frame, meansmounting the shaft on the base frame for rotation, actuating means forrotating the shaft and means carried by the shaft adjacent each supportand on which the flexible elements are disposed for movements in unisonresponsive to rotation of the shaft.

7. The invention of claim 6, wherein said last-named means includes adrum means on the shaft adjacent each support and disposed immediatelyadjacent the lower pulleys so that the flexible elements pass from thedrum means to guided positions on the lower pulleys.

8. The invention of claim 7, wherein said base frame has a side and saidshaft is positioned lengthwise of the base frame in adjacency to theside. I

9. The invention of claim 8, wherein said actuating means for the shaftcomprises a pinion fixed on the shaft intermediate the drums, a driveshaft, means carried by the side of the base frame rotatably supportingthe drive shaft transversely thereof, said drive shaft carrying a Wormgear enmeshed with the pinion and means for rotating said drive shaft.

10. The invention of claim 1, wherein steerable wheel assemblies areattached to each end section of the base frame and mobily support thebase frame, draft connection means carried by each wheel assembly fordetachable connection to a draft vehicle, said draft connection meansbeing selectively employable so that the base frame can be drawn fromeither end section and means associated with each wheel assembly and theassociated draft connection means for retaining the draft connectionmeans in an inoperative position and rendering the associated wheelassembly non-steerable when the draft connection means on the oppositeend section is in use.

11. The invention of claim 1, wherein said mounting means for thesupports comprises means carried by the base frame and connected to thelower ends of the supports for mounting the supports for pivotalmovement from an upright position into generally horizontally collapsedpositions resting lengthwise on the base frame longitudinally thereof.

12. The invention of claim 12, wherein said supports are pivotallymounted in slightly offset relation longitudinally of the base frame sothat in upright positions they are in substantial alignment consideredlengthwise of the base frame but in collapsed positions they liealongside each other on the base frame.

13. The invention of claim 1, wherein means is provided for preventingrotational movement of the supporting members relative to the supportsand for guiding the supporting members in firm rectilinear slidingmovements on the supports.

14. The invention of claim 1, wherein said supporting members have sidesfacing toward the end sections and opposing sides facing in oppositeoutward directions longitudinally of the base frame and said meansattaching the flexible elements to the supporting members includes hookelements carried by said last sides adjacent the lower ends of thesupporting members.

15. The invention of claim 14, wherein said platform assembly comprisesan arm laterally projecting from each supporting member adjacent theupper end thereof and References Cited disposed transversely of thelongitudinal axis of the base UNITED STATES PATENTS frame, said armsextending in the same direction substantially normal to h id carryingthe hook elements and 657392 9/1900 Curley 92-145 being complementarilyand cooperativ ly disposed, Said 5 $232; if- 1:3:3; platform havingopposing en means femovably mount 3 5 11/1964 5 22 55 182-146 ing theplatform ends on the arms so that the platform a 3,323,616 6/1967 Best182--146 is supported thereby in a honzontal position and guard railmeans associated with the platform. REINALDO P. MACHADO, PrimaryExaminer.

1. A SCAFFOLD COMPRISING AN ELONGATED BASE FRAME HAVING OPPOSING ENDSECTIONS, AN ELONGATED TUBULAR SUPPORT CARRIED BY THE BASE FRAMEADJACENT EACH END SECTION, MEANS MOUNTING THE SUPPORTS ON THE BASE FRAMEFOR POSITIONING OF THE SUPPORTS IN RIGID UPRIGHT POSITIONS AND DISPOSEDSUBSTANTIALLY IN ALIGNMENT LONGITUDINALLY OF THE BASE FRAME, EACHSUPPORT HAVING AN UPPER AND A LOWER END, A SUPPORTING MEMBER SLIDABLYSLEEVED ON EACH SUPPORT, A PLATFORM ASSEMBLY CARRIED BY THE SUPPORTINGMEMBERS AND INCLUDING A SUBSTANTIALLY HORIZONTALLY DISPOSED PLATFORMOVERLYING THE BASE FRAME AND EXTENDING BETWEEN THE SUPPORTS, ROTATABLEWINDING MEANS CARRIED BY THE BASE FRAME, A PAIR OF ELONGATED FLEXIBLEELEMENTS WOUND ON AND ACTUATED BY THE WINDING MEANS IN SYNCHRONIZEDFASHION, A LOWER GUIDE MEANS DISPOSED BELOW THE LOWER END OF EACHSUPPORT, AN UPPER GUIDE MEANS CARRIED BY THE UPPER END OF EACH SUPPORT,ONE OF SAID FLEXIBLE ELEMENTS BEING PASSED UNDER THE LOWER GUIDE MEANSFOR ONE SUPPORT AND EXTENDING MOVABLY UPWARDLY IN THE ONE SUPPORT ANDBEING PASSED DOWNWARDLY OVER THE UPPER GUIDE MEANS ON THE ONE SUPPORTEXTERNALLY OF THE SUPPORT, THE OTHER OF SAID FLEXIBLE ELEMENTS BEINGPASSED UNDER THE LOWER GUIDE MEANS FOR THE OTHER SUPPORT AND EXTENDINGMOVABLY UPWARDLY IN THE OTHER SUPPORT AND BEING PASSED DOWNWARDLY OVERTHE UPPER GUIDE MEANS ON THE OTHER SUPPORT EXTERNALLY OF THE SUPPORT,AND MEANS ATTACHING THE FLEXIBLE ELEMENTS TO THE SUPPORTING MEMBERS FORMOVING THE SUPPORTING MEMBERS IN CONSORT ON THEIR ASSOCIATED SUPPORTS.